They "work" fine. That is, their purpose is to provide support for that modern hardware and they do just that. But understand the PCI bus is antique (legacy) technology, and as such is very slow compared to today's. Depending on your motherboard, the PCI bus has a maximum speed of 33 - 66MHz for a maximum data transfer rate of 533Mb/sec. USB 3.0 can transfer (in theory) up to 4.8 Gb/sec and eSATA using an SATA 6 drive, up to 6Gb/sec. So while this adapter will allow those newer devices to function, the bottleneck created by the PCI bus will greatly degrade their performance. Think of a 6 lane highway suddenly narrowing down to 2 lanes.
That said, if buying new USB or SATA devices today, buy the latest and greatest so you can carry them over to a new computer.
Also note that USB 3.0 devices are backwards compatible with previous version ports. So if your computer has any USB connections, you can still connect a USB 3.0 device to it. If your current computer does not have any USB support, then it is probably pretty dated, and it is probably time to start budgeting for something newer.